blocks|key|216615|text|在编写基于Scala的JavaFX应用程序时，有几件事需要知道。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|216616|首先，这是一个示例hello+world应用程序：|216617|import+javafx.application.Application
import+javafx.scene.Scene
import+javafx.scene.layout.StackPane
import+javafx.stage.Stage
import+javafx.scene.control.Label

class+Test+extends+Application+{
++println("Test()")

++override+def+start(primaryStage:+Stage)+{
++++primaryStage.setTitle("Sup!")

++++val+root+=+new+StackPane
++++root.getChildren.add(new+Label("Hello+world!"))

++++primaryStage.setScene(new+Scene(root,+300,+300))
++++primaryStage.show()
++}
}

object+Test+{
++def+main(args:+Array[String])+{
++++Application.launch(classOf[Test],+args:+_*)
++}
}|code-block|syntax|javascript|216618|运行它，你应该会得到：|216619|​|216620|📷|atomic|offset|length|216621|216622|下面是一个用Java语言编写的官方hello+world示例：http://docs.oracle.com/javafx/2/get_started/hello_world.htm|216623|主要区别是：|216624|启动实际application.|216625|You的def+main()必须指定它将在|unordered-list-item|style|CODE|216626|的上下文中运行，而不是伴生对象：def+main()|216627|216628|216629|如果你只是尝试用Application.launch(args+:+_*)直接运行应用程序，你会得到这个错误：|216630|线程"main“中出现|216631|异常java.lang.RuntimeException:错误:+class+Test$不是javafx.application.Application的子类|blockquote|216632|216633|216634|要了解有关JavaFX的更多信息，只需阅读官方文档：http://docs.oracle.com/javafx/index.html|216635|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/65cfb9e0d19ba4d4eb78f543df9c3c8a.png|imageAlt|1|LINK|MUTABLE|url|http://docs.oracle.com/javafx/2/get_started/hello_world.htm|2|http://docs.oracle.com/javafx/index.html^0|0|0|0|0|0|0|1|0|0|0|V|1N|1|0|0|0|4|A|0|G|A|0|0|0|8|T|0|0|0|0|0|Q|14|2|0^^$0|@$1|2|3|4|5|6|7|1Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1Z|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|20|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|21|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|22|8|@]|9|@]|A|$]]|$1|M|3|N|5|O|7|23|8|@]|9|@$P|24|Q|25|1|26]]|A|$]]|$1|R|3|L|5|6|7|27|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|28|8|@]|9|@$P|29|Q|2A|1|2B]]|A|$]]|$1|U|3|V|5|6|7|2C|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|2D|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|10|7|2E|8|@$P|2F|Q|2G|11|12]]|9|@]|A|$]]|$1|13|3|14|5|10|7|2H|8|@$P|2I|Q|2J|11|12]]|9|@]|A|$]]|$1|15|3|-4|5|6|7|2K|8|@]|9|@]|A|$]]|$1|16|3|-4|5|6|7|2L|8|@]|9|@]|A|$]]|$1|17|3|18|5|6|7|2M|8|@$P|2N|Q|2O|11|12]]|9|@]|A|$]]|$1|19|3|1A|5|6|7|2P|8|@]|9|@]|A|$]]|$1|1B|3|1C|5|1D|7|2Q|8|@]|9|@]|A|$]]|$1|1E|3|-4|5|6|7|2R|8|@]|9|@]|A|$]]|$1|1F|3|-4|5|6|7|2S|8|@]|9|@]|A|$]]|$1|1G|3|1H|5|6|7|2T|8|@]|9|@$P|2U|Q|2V|1|2W]]|A|$]]|$1|1I|3|-4|5|6|7|2X|8|@]|9|@]|A|$]]]|1J|$1K|$5|1L|1M|1N|A|$1O|1P|1Q|-4]]|1R|$5|1S|1M|1T|A|$1U|1V]]|1W|$5|1S|1M|1T|A|$1U|1X]]]]

There are a few things to know when writing Scala based JavaFX applications.

First, here's a sample hello world app:

<pre><code>import javafx.application.Application
import javafx.scene.Scene
import javafx.scene.layout.StackPane
import javafx.stage.Stage
import javafx.scene.control.Label

class Test extends Application {
 println("Test()")

 override def start(primaryStage: Stage) {
 primaryStage.setTitle("Sup!")

 val root = new StackPane
 root.getChildren.add(new Label("Hello world!"))

 primaryStage.setScene(new Scene(root, 300, 300))
 primaryStage.show()
 }
}

object Test {
 def main(args: Array[String]) {
 Application.launch(classOf[Test], args: _*)
 }
}
</code></pre>

Running it you should get:

<img src="https://i.stack.imgur.com/WlxmA.png" alt="enter image description here">

Here's an official hello world example in Java: <a href="http://docs.oracle.com/javafx/2/get_started/hello_world.htm" rel="noreferrer">http://docs.oracle.com/javafx/2/get_started/hello_world.htm</a>

The main differences are:

<ul>
<li>You have to write the so-called companion object with the <code>def main()</code> that launches the actual application.</li>
<li>You have to specify that it will be run in context of the class Test, and not the companion object: <code>Application.launch(classOf[Test], args: _*)</code>.</li>
</ul>

If you just try to run the application directly with <code>Application.launch(args : _*)</code> you will get this error:

<blockquote>
 Exception in thread "main" java.lang.RuntimeException: Error: class
 Test$ is not a subclass of
 javafx.application.Application
</blockquote>

To learn more about JavaFX, just read the official documentation: <a href="http://docs.oracle.com/javafx/index.html" rel="noreferrer">http://docs.oracle.com/javafx/index.html</a>

blocks|key|216353|text|我能够在scala_swing中更令人满意地解决这个问题，因为你可以用参数实例化一个实例，然后在它上面调用main来启动Swing。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|216354|此解决方案允许在FX应用程序中以使用静态变量和可能的其他问题为代价来获取参数。其一，这肯定不是多线程安全的。|216355|package+hack

/**
++*+Created+by+WorkDay+on+8/11/16. 
++*+ 
++*+HelloTest+shows+a+method+which+allows+parameters+to+be+passed
++*+into+your+javaFX+application+as+it+is+started
++*+this+allows+it+to+be+connected+to+non-FX+code+that+existed+before+it.
++*
++*+You+could+also+pass+a+reference+to+the+Application+back
++*+into+the+non-FX+code+if+needed.
++*/

import+javafx.application.Application
import+javafx.scene.Scene
import+javafx.scene.layout.StackPane
import+javafx.stage.Stage
import+javafx.scene.control.Label

case+class+Data(data:+String)

object+SomeOtherCode+extends+App+{
++HelloTest.launch(Data("brave"),+Data("new"))
}

object+HelloTest+{
++var+data1:+Data+=+_
++var+data2:+Data+=+_
++def+launch(data1:+Data,+data2:+Data)+=+{
++++HelloTest.data1+=+data1
++++HelloTest.data2+=+data2
++++Application.launch(classOf[HelloTest])
++}
}

private+class+HelloTest+extends+Application+{
++val+data1:+Data+=+HelloTest.data1
++val+data2:+Data+=+HelloTest.data2


++override+def+start(primaryStage:+Stage)+{
++++primaryStage.setTitle("Sup!")

++++val+root+=+new+StackPane
++++root.getChildren.add(new+Label(s"Hello+${data1.data}+${data2.data}+world!"))

++++primaryStage.setScene(new+Scene(root,+300,+300))
++++primaryStage.setX(0)
++++primaryStage.setY(0)
++++primaryStage.show()
++}
}|code-block|syntax|javascript|216356|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I was able to solve this problem in scala_swing much more satisfactorily because you could instantiate an instance with parameters then call main on it to start Swing later. 

This solution allows parameters to be obtained in the FX application at the cost of using static var and possible other issues. One being that this is surely not multi-thread safe.

<pre><code>package hack

/**
 * Created by WorkDay on 8/11/16.&lt;br&gt;
 * &lt;br&gt;
 * HelloTest shows a method which allows parameters to be passed
 * into your javaFX application as it is started
 * this allows it to be connected to non-FX code that existed before it.
 *
 * You could also pass a reference to the Application back
 * into the non-FX code if needed.
 */

import javafx.application.Application
import javafx.scene.Scene
import javafx.scene.layout.StackPane
import javafx.stage.Stage
import javafx.scene.control.Label

case class Data(data: String)

object SomeOtherCode extends App {
 HelloTest.launch(Data("brave"), Data("new"))
}

object HelloTest {
 var data1: Data = _
 var data2: Data = _
 def launch(data1: Data, data2: Data) = {
 HelloTest.data1 = data1
 HelloTest.data2 = data2
 Application.launch(classOf[HelloTest])
 }
}

private class HelloTest extends Application {
 val data1: Data = HelloTest.data1
 val data2: Data = HelloTest.data2


 override def start(primaryStage: Stage) {
 primaryStage.setTitle("Sup!")

 val root = new StackPane
 root.getChildren.add(new Label(s"Hello ${data1.data} ${data2.data} world!"))

 primaryStage.setScene(new Scene(root, 300, 300))
 primaryStage.setX(0)
 primaryStage.setY(0)
 primaryStage.show()
 }
}
</code></pre>

blocks|key|213457|text|您可以使用这种方式。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|213458|+class+BuildFx+extends+Application{

++override+def+start(primaryStage:+Stage):+Unit+=+{
++++primaryStage.setTitle("Scala")
++++var+btn=new+Button("Say+Hello+Scala")
++++val+root=new+StackPane()
++++root.getChildren().add(btn)
++++primaryStage.setScene(new+Scene(root,+300,+300))
++++primaryStage.show()

++}



++def+launchIt():Unit={
++++Application.launch()
++}

}

///////////////////////////////////////////////////////////
object+Init{


++def+main(args:+Array[String]):+Unit+=+{
++++val+buildFx=new+BuildFx
++++buildFx.launchIt()

++}
}|code-block|syntax|javascript|213459|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can use this way. 

<pre><code> class BuildFx extends Application{

 override def start(primaryStage: Stage): Unit = {
 primaryStage.setTitle("Scala")
 var btn=new Button("Say Hello Scala")
 val root=new StackPane()
 root.getChildren().add(btn)
 primaryStage.setScene(new Scene(root, 300, 300))
 primaryStage.show()

 }



 def launchIt():Unit={
 Application.launch()
 }

}

///////////////////////////////////////////////////////////
object Init{


 def main(args: Array[String]): Unit = {
 val buildFx=new BuildFx
 buildFx.launchIt()

 }
}
</code></pre>

Is there some guide or walkthrough to building a Scala + JavaFX desktop application?

I'm having hard time finding a good source and I am using IntelliJ IDEA as the IDE.

Even the most simplistic desktop hello world samples would help a lot, because I have little clue where to start.

Update: This is what I have now:

<pre><code>import javafx.application.Application
import javafx.scene.Scene
import javafx.scene.layout.StackPane
import javafx.stage.Stage
import javafx.scene.control.Label

class Test extends Application {
 override def start(primaryStage: Stage) {
 primaryStage.setTitle("Sup!")

 val root = new StackPane
 root.getChildren.add(new Label("Hello world!"))

 primaryStage.setScene(new Scene(root, 300, 300))
 primaryStage.show()
 }
}

object Test {
 def main(args: Array[String]) {
 val t = new Test
 t.start(new Stage)
 }
}
</code></pre>

Running it I get:

<blockquote>
 Exception in thread "main" java.lang.IllegalStateException: Not on FX
 application thread; currentThread = main
</blockquote>

How can I get it to display the hello world window with the label?

Getting started on Scala + JavaFX desktop application development

集成开发环境

IntelliJ IDEA

Java

是否有一些构建Scala + JavaFX桌面应用程序的指南或演练？我很难找到一个好的源码，我正在使用IntelliJ IDEA作为集成开发环境。即使是最简单的桌面hello world示例也会有很大帮助，因为我几乎不知道从哪里开始。更新：这是我现在所拥有的：import javafx.application.Appl...

问Scala + JavaFX桌面应用程序开发入门
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Scala + JavaFX桌面应用程序开发入门EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Scala + JavaFX桌面应用程序开发入门
EN